Transcriber selection circuit for magnetic drum memory



Nov. 17, 1959 R. THORENSEN EI'AL TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY COMPUTER COMPU TEE CON TEOL-S 19 Sheets-Sheet 1 E EEG/.5 TEE C R EGLST FE I l I S- REGISTER EL E C TEOSTATIO MEMORY Bldg /0 new SELECTION MATEIX, UM PLAYBACE AND MAGNETIC o2 eecoeome clecums TIMING TRACK 700, mum's seusenoa I: woesss couurez l r J 1202 MAGNETIC oeun menoev rems ez coureoLs couurse TEAMSFEE EEGkSTEQ 1NVENTOR5 Fog/70W Tho/"amen [0 1? flmbmszb Miiiwl A TTOP/VEY 465A Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY l9 Sheets-Sheet 2 Original Filed Dec. 1. 1953 INVENTORS 0 H Wm MT mm mm M m am A m W m Wm fi wx Nov. 17, 1959 R. THORENSEN ETAL 2,913,705

TRANSCRIBBR SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 3 I NVENTORS Fag/70F Thom/wen 10915 F flmbmsz'o BY M4 a a I Kl TTOENE V Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 4 WRITE GATE I N VENTORS Fag/var Tho/amen 1310 12) F Ambmszb Nov. 17, 1959 R. THORENSEN ETAL TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 5 I r----+---- -I---++-; l N g l g 3 1 l a. Q? i i l l b u N i 5% I l a I I Il m-: -fi I E l R i i T l i I 1 1 I Ff ll 5 [5 r x T l he 2: N l N I 8 E; 5 1; a u f K\ E m an N J I I r E 5 Q 1 t T T i T .N L b i 1 PH I a g 1% E i5 5 I? g i g 1 I T i J R r l- INVENTORY: Fag/20x 2770/19/56 8 5 l3zyzbiflmbrwzo P Q BY Z Z k ATTORNEY M i,

Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 6 5 mm w m we WV A 8% w 7A Pi. m m A h mam v. B add Tn 33 3Q: Ti

u 31m $5.: Na

Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR mcnznc DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 7 INVENTORS fag/7a! Thom/15m BY Bing/'0 Fflmbmszb M ATTOPA/[y A6EN T Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION cmcun FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 8 INVENI'OR-S ATTOEl/EY M M AGENT Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY 19 Sheets-Sheet 9 Original Filed D00. 1. 1953 INVENTORS Wag/701 From/r5017 E1092 flmbmm M M r w 5237 Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION cmcurr FOR MAGNETIC DRUM MEMORY Original Filed Doc. 1. 1953 19 Sheets-Sheet 10 INVENTORS Fey/70F Thom/75m A TTOFNEY AGE/V 7 Nov. 17, 1959 R. THORENSEN EI'AL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY 19 Sheets-Sheet 12 Original Filed Dec. 1. 1953 0 .0 Y m w w m m 1D T V 1M m n M W. A r I M w M m6 k R DA 5 WT. at w w 23 Na: M U m U W Y a S! on! m! a! B 3.2 v v I O u v! @Q! 1! n?! N?! k QNP 1 1| l I IIJ 38 "R 0.! illlfilii|f|l|lllllll lllllllll vllulllllL M 3 hm m m is 2 L a3 2 QR St 23 8! a at at 3 n 93 l I i I l ||ll i i I l I I I ||IL 3 Nov. 17, 1959 R. THORENSEN EI'AL 2,913,706

mmscmsan smzc'non cmcuxr FOR mcus'rzc mum MEMORY 19 Sheets-Sheet 14 Original Filed D90. 1. 1953 INVENTORS Fag/var Thane/wen 10910 1? Arab/1051b BY a M i M A TTOENfY' MEN? Nov. 17, 1959 R. THORENSEN ETAI. 2,913,706

TRANSCRIBER szmzcnou cmcurr FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 15 INVENTORS Ragnar Thormsen Hay/0 [limb/1951b M M 1 141 QB @3335 mfid V V 353m 1 5x6 zocacm misc m3 m3 Eh I1. I l mu a. mo mow non 2h 1| I at a. no m9 wuzwamw .PmEn Hutu? same :Smo E 51.50 was mom Q25;

3; TOKNEY AGENT NOV. 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY 19 Shuts-Sheet 16 Original Filad Dec. 1. 1953 20: QWQO 435R SEE was 933 5 03G laq g ml Q22 62% Ian @382. 3ND

mvsmons Ragnar ihorensen .Biqg/o i. Ambroszb 2 Arm/qua m AGE,

Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 17 Li COMPUTEE (ON TEOLS 1N VENTORJS Kay/var Tho/"mam BY MW A TTORWE Y M M AGENT Nov. 17, 1959 R. THORENSEN El AL 2,913,706

TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 1B QQ ELECTROSTATIC memorav 0 MEM 02 Y CON TKOL M EEG/GTE E DRUM DRIVERS R EEGITEE READING AND I'VE/HUG CONTROL 2 Cow/r52 A0026: COUMTEe INVENTORS Ragnar Thom/7520 F 20 Biogzb 1. flmbrusz'o BY M k g ATTOP/Vfy AGENT Nov. 17, 1959 R. THORENSEN ETAL 2,913,706

TRANSCRIBER SELECTION cmcurr FOR MAGNETIC DRUM MEMORY Original Filed Dec. 1. 1953 19 Sheets-Sheet 19 a B 7 5 I Specifies CR1 Specifies R0. of Specifies 6m Ior drul Opention line 1111' Iorda tnnsfemd channel cc-ndl iylbol mu 0 1| 5 is write 0010 0000 32 words 01110000 Rad 0001 0100 Ono 16 words 1100 1101 1110 8 yards 1111 I 0B1 mane digits motion Dru! m1 3 1': has: 0pmline 1 mm of n spec'- dlgita tion p111- chnnel o 11: 1 we].

:- inmed INVENPORS Fog/var" Tho/"arisen Bz'qgw EAmbmsz'o United States Patent TRANSCRIBER SELECTION CIRCUIT FOR MAGNETIC DRUM MEMORY Ragnar Thorensen and Biagio F. Ambrosio, Los Angeles, Calif., assignors to the United States of America as represented by the Secretary of Commerce Original application December 1, 1953, Serial No. 395,638. Divided and this application August 1, 1956, Serial No. 601,598

6 Claims. (Cl. 340-174) The present invention relates to a magnetic drum memory for use with electronic computers and in particular to control circuitry for such a unit that greatly reduces the overall access time to the drum memory.

The present invention is a division of application Serial No. 395,638, Magnetic Drum Memory for Electronic Computers, filed December 1, 1953, in the names of Ragnar Thorensen, William R. Arsenault, and Biagio F. Ambrosio.

In the modern electronic computer, an internal memory is utilized for storage of information not being currently used. Memories such as the electrostatic type of storage system are very rapid and their operation can be synchronized with the basic repetition rate of the computer. Ideally all computers would have such a memory large enough to handle all information that might be necessary for obtaining the complete solution to a particular problem. However, the expense involved in providing an electrostatic memory capable of handling the most complex problem would be prohibitive. Therefore it is often necessary to provide an auxiliary memory system for computers which, although slow as compared to the electrostatic memory, is far cheaper to build and maintain.

The magnetic drum memory system can provide a very large quantity of storage for a relatively low cost, since all of the circuitry and machinery involved is easily maintained as compared to the circuitry necessary for an electrostatic memory. As previously pointed out, however, the magnetic drum type of memory is relatively slow and cannot be operated in synchronism with the computer. In particular if information is required from some small specific location in the drum, the computer may have to wait up to a maximum of one drum revolution before receiving any information. This waiting time, or access time, is measured in milliseconds as compared with only a few microseconds for the internal electrostatic memory. In order to improve such situation means are provided to transfer information in sizeable blocks from the magnetic drum memory to the electrostatic memory, thus minimizing the total number of referrals. The blocks of information are arranged on the drum to cut down any dead waiting time for the drum, that is, the time taken for the drum to come to a specific position before transcribing can occur. The information comprising a block is stored sequentially around the circumference of the drum so that each block completely fills a respective band or channel on the drum. When a transfer to or from the drum memory is made, the entire channel is handled at one time and transfer of information starts immediately after the desired channel has been selected and continues for exactly one revolution of the drum, thus eliminating waiting time.

It is therefore the primary object of the present invention to provide a magnetic drum memory system in which the access time to the drum memory is held to a minimum.

Another object of the present invention is to provide "ice a magnetic drum memory system in which the address of the particular word passing under the reading and writing heads is known at all times and is available to the control circuitry of the computer immediately upon the receipt of the drum operation signal.

Another object of the present invention is to provide a magnetic drum memory system in which the information recorded on the drum is grouped in words, there being a predetermined number of words in a single channel of the drum, and in which a complete drum operation consists of reading or writing a complete channel from or on the drum.

Another object of the present invention is to provide a magnetic drum memory system in which designated half and quarter channels may be read into the computer during a given drum operation.

Another object of the present invention is to provide a magnetic drum storage system in which there is an equality between the number of words in a single channel of the drum and a predetermined number of complete lines of the electrostatic memory.

Another object of the present invention is to provide a magnetic drum memory system in which the coder may choose the particular consecutive lines of the electrostatic memory to be communicated with while the drum system controls the particular location in those lines at which the transfer of information is to start.

Other uses and advantages of the invention will become apparent upon reference to the specification and drawings.

Fig. l is a simplified block diagram of the magnetic drum memory system of the present invetnion;

Fig. 2 is a circuit diagram of the flip-flop circuit used in the present invention;

Fig. 2A shows the symbol for the circuit of Fig. 2 when it is connected as a single input flip-flop;

Fig. 2B shows the symbol for the circuit of Fig. 2 when it is connected so that separate pulses must be used to cause the circuit to flip;

Fig. 3 is a wiring diagram of the pulse gate used in the present invention;

Fig. 3A shows the symbol used for the circuit of Fig. 3 when a positive input produces a positive output;

Fig. 4 is a wiring diagram of the read gate used in the present invention;

Fig. 4A shows the symbol used for the read gate of Figure 4;

Fig. 5 is a Wiring diagram of the direct-current gates used in the present invention;

Fig. 5A shows the symbol used for the D.-C. gates of Figure 5;

Fig. 6 is a wiring diagram of the write gate of the present invention.

In Figs. 2-6 above, the symbol appearing in juxtaposition to the wiring diagram is the symbol which will be used in Figs. 7-14 to designate that particular circuit.

Figs. 7-14 are wiring diagrams which constitute a complete circuit diagram of the drum system of the present invention.

Figs. 15 and 16 constitute a single graph of the timing wave forms for an input from the drum to the electro static memory, or a read operation.

Figs. 17 and 18 constitute a single graph of the timing wave forms for an output from the eletcrostatic memory to the drum, or a write operation.

Figs. 19 and 20 constitute a complete block diagram of the system of the present invention.

Figs. 21 and 22 are tables illustrating the significance of a word when employed as an instruction in the C register.

The magnetic drum of the present invention is an 

